Ive got low vac as well on my engine and have had a canister for roughly 18 years and it solved my problem. I have a vac gauge in the dash which is showing my canister vac at all times just for giggles (but it does let me know that I have no leaks as well). The canister will get, and hold, a good amount and then dip down when you apply the brakes. Without the canister I can hardly stop. My car is an 86 gm monte carlo. It regains the vac within a few seconds

Price?? That aluminum one is pretty but not doing much more than the cheapest "can". Mine is some ugly yellow coffee can sized canister with a one way valve keeping the "hg" in the can

EDIT: ooops, youre showing a vac pump I think, I was referring to the aluminum canisters they sell.